1. Field of the Invention
The present invention relates to a fuel container with a pipe. More particularly, the present invention relates to a fuel container having a pipe connecting piece with a rim and a pipe having an annular bead on which a connecting member acts, and a sealing ring further being seated between the rim and the annular bead.
2. Description of the Related Art
In order to avoid emissions, the connection between a fuel container and pipe should not only be liquid-tight but also gas tight. This also includes a requirement that as little fuel vapors as possible should diffuse through the seals between the fuel container and pipe.
In applicant""s co-pending application GM 41/2000 for an Austrian registered design, a connection between two pipe parts for the same purpose is proposed, and has the features of the preamble. In the case of this connection, only one sealing ring is provided, which forms a semi-radial seal and therefore also has to be compressed in the axial direction, to the detriment of its sealing action. Since the sealing ring is contacted by fuel vapors on one side and, on the outer side, is connected to the ambient air, fuel vapors are able to diffuse through it.
In addition, during assembly this arrangement can lead to a nonuniform seat or even to damage to the sealing ring, particularly if the pipe is inserted crookedly or if there is a lack of axial guidance. In addition, the connection should also be easy to produce and to release again, even at locations of difficult access, and without overcompressing the sealing ring, which is not ensured in the case of the semi-radial position and the uncontrollable tightening torque on the nut. The act of compression by means of a union nut is complicated and requires that the union nut be put on before the annular bead is formed, and in addition the connection can loosen during operation. Finally, in the case of this known arrangement, it is not beneficial to provide a second sealing ring, since this would be complicated in design terms and would reduce the clear diameter.
It is therefore an object of the invention to remedy these disadvantages and to improve the connection to the effect that, with minimum constructional expenditure, it can be produced and also released again simply and accurately and, in addition, is quite tight.
According to one aspect of the invention, this is achieved by the pipe, on the side of the annular bead facing the pipe connecting piece, forming a cylinder with two circumferential grooves, in each of which a sealing ring is seated, which rests in a sealing manner on the cylindrical inner surface of the pipe connecting piece, and by the annular bead having a cross section with two oblique flanks, the conically widened rim of the pipe connecting piece resting on the flank facing the pipe connecting piece, and the connecting member acting on the flank facing away.
Therefore, during assembly, the sealing rings are no longer pressed together to a predetermined extent in the radial direction during assembly, which means that they can no longer be overcompressed. This arrangement also makes it possible to provide two sealing rings on the same radius, that is to say to improve the sealing substantially, without reducing the clear width. The sealing rings can be premounted in the radial grooves on the pipe, which then merely has to be plugged into the pipe connecting piece. The widened rim of the pipe connecting piece prevents damage to the sealing ring during assembly. The flank of the annular bead facing the pipe connecting piece rests on the conically widened rim of the pipe connecting piece. As a result, a true-angle connection is provided and a certain sealing action is also already achieved, which ensures that the outer sealing ring is not in contact with the surroundings and that, in this way, by impoverishing the space in front of and behind this sealing ring, diffusion is also brought to a standstill, and the impoverishment also simultaneously constitutes a safeguard against contamination.
In a development of the invention, the cross section of the grooves is circular, the radius of the circle being greater than that of the sealing rings. As a result, not only are the sealing rings looked after, but also the sealing action is improved, since the sealing ring, pressed together radially during assembly, then fills the entire area of the groove. The greater radius of the grooves results in a particularly narrow gap in the second sealing stage. In order to maximize the sealing action, the first sealing ring, closer to the fuel container, can comprise a fuel-resistant elastomer, and the more remote second sealing ring can comprise an elastomer with a vapor barrier action.
In an advantageous embodiment of the invention, the connecting member is a clip which is open at at least one point and, in cross section, has two oblique flanks, one of which rests on the conically widened rim of the pipe connecting piece and the other rests on that flank of the annular bead which faces away from the pipe connecting piece. Because the conical widening of the pipe connecting pipe rests on the oblique flank of the pipe, and because of the radial sealing, the compression force during assembly does not need to be limited. This permits the use of a clip which, in cooperation with the two oblique flanks, ensures a firm connection. However, other connecting members are also conceivable. In a development of this embodiment, the clip comprises two halves each forming a semicircle and connected to each other at their ends and having, at their ends, radially outwardly projecting ears, one ear being longer in the radial direction and one being shorter, and the connection being produced by folding the longer ear around the shorter. In this way, the halves of the clip can be positioned in one operation and also firmly connected to each other at the same time. Nevertheless, the connection can also be released again easily by bending the ears up. If, finally, each half of the clip has a long ear at one end and a short ear at the other end, the two halves of the clip are identical parts.